This invention relates generally to cutting tools for cutting metal stock. More particularly, the invention relates to a cut-off blade having a one-piece construction of a carbide material.
Cut-off blades or cutting tools may be used in turret lathes, in engine lathes and in other automatic lathes for cutting bulk stock material such as stainless-steel.
One-piece constructed cut-off blades consisting of a cobalt material are currently available for machine tooling. An example of the single piece cobalt cutting tool is the Mo-Max or Mo-max cobalt tool, manufactured by the Cleveland Co., Cleveland, Ohio. The Mo-Max cutting tool features a single piece cobalt construction with the front and/or rear face beveled at 10.degree.. The Mo-max cobalt tool also features converging sides making the configuration of the tool substantially V-shaped. However, these one piece constructions are typically used for cutting softer metals than those which can be cut by the present invention.
Cutting tools currently in use and including carbide for cutting relatively hard metal stock combine a steel shank with a relatively small carbide cutting tip brazed to one end of the steel shank. This construction has exhibited several serious shortcomings. For example, the heat of brazing apparently changes the temper or grade of the carbide and may cause the carbide to crack. Further, brazing provides somewhat of a weak joint between the two materials, this permitting the carbide to vibrate, which may result in chipping. Also, manufacturing the cutting tool in two parts and then joining those two parts together in a brazing operation drives the cost of the device up and provides a greater chance of error in the finished product.
A further disadvantage of the two-piece carbide tip, steel shaft construction is the limited life of the cutting tool. This limited life may result in a variety of ways. First, the carbide tip can only be trimmed back approximately 1/2 inch and this inherently limits its cutting capabilities. Second, the brazing joint may fail and thereby enable the carbide insert to break away from the shaft. Third, the shaft portion supporting the insert may completely shear or seriously bend. All three of these conditions render the cutting tool inoperable and risk the danger of the steel shank tearing against the metal stock, thereby causing serious damage to the stock.
Accordingly, the prior art devices exhibit many shortcomings which have heretofore remained unsolved.